1. Field of the Invention
This invention relates to composite slabs constructed from metal cellular sections and concrete, and more particularly to composite slabs useful as building floor or roof structures wherein the concrete is disposed within the cells of the cellular sections and there is a composite relationship between the concrete and the metal cellular sections.
2. Description of the Prior Art
The use of metal cellular sections in the construction of vertical wall structures is known in the art. For example, certain cells of abutting or intersecting metal cellular wall sections may be filled with concrete to rigidly connect the metal cellular wall sections together, see U.S. Pat. No. 2,049,862 (PALMER). The bottom portions of cells of metal cellular wall sections have been partially filled with concrete to anchor the metal cellular wall sections to a concrete pad, see U.S. Pat. No. 2,200,636 (PALMER). Metal cellular wall sections having perforations adapted to receive reinforcing elements such as steel rods, conduits and the like have been filled with concrete whereby the reinforcing elements interlock the metal cellular wall sections in load transmitting relation, see U.S. Pat. No. 2,049,863 (PALMER).
Spaced studs, beams and plates have been assembled to provide a skeleton wall or a floor having hollow spaces filled with plastic meterial, such as concrete, see U.S. Pat. No. 930,610 (PELTON).
Floor structures are known wherein the concrete achieves a positive mechanical combination with the metal subfloor, see U.S. Pat. Nos. 3,397,497 (Y. R. SHEA, Aug. 20, 1968); 3,812,636 (R. E. ALBRECHT et al., May 28, 1974) and Canada Pat. Nos. 704,839; 704,840; 704,841; 704,842 (B. E. CURRAN et al., Mar. 2, 1965). These prior art floor structures each comprise a metal subfloor assembled from plural cellular and non-cellular sheet metal flooring sections, and an overlying layer of concrete. The metal subfloor has been subject to damage by concrete pouring equipment, such as concrete buggies, large bottom dump buckets, wheelbarrows, foot traffic, and the like. Such equipment places heavy, concentrated loads and impact loads on the metal subfloor. The metal subfloor provides the normal concrete reinforcement for positive loads. It is customary to embed metal wire fabric to minimize surface cracking of the concrete. Generally, negative reinforcing steel is not provided and consequently the composite slab is designed as a series of single spans notwithstanding the fact that the composite slab may extend continuously between end supports and across intermediate supports. Once the concrete is poured extensive concrete finishing operations are required. The freshly poured concrete must be allowed to cure and must while curing be adequately protected against rapid drying of the exposed concrete surface. Wet concrete fill operations required by conventional composite floor slab construction are expensive and time-consuming.
The structures disclosed by SHEA, ALBRECHT et al, and CURRAN et al cannot conveniently be employed as an inclined roof or as a ramp. Confinement of the layer of concrete poured onto the inclined metal subfloor would be extremely difficult and expensive to achieve.